What is pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) is a chronic, rare condition that develops from changes in the walls of the pulmonary arteries, making them more narrow and stiff.

Many patients are young when the disease develops. PAH may have no known cause. Sometimes, it can be inherited (passed from parents to children) or caused by heart disease that is evident at birth.

Treatment for PAH often depends on the stage and severity of the disease. The World Health Organization (WHO) classifies patients who have PAH into 4 functional classes. The higher the class, the more severe the disease and the greater urgency for diagnosis and treatment.

CLASS I

Physical activity is not limited. Ordinary physical activity does not cause shortness of breath, chest pain or discomfort, or a feeling tiredness or faintness.

CLASS II

The patient is comfortable at rest, but ordinary physical activity causes shortness of breath, chest pain or discomfort, or a feeling of tiredness or faintness.

CLASS III

The patient is comfortable at rest, but less than ordinary physical activity causes shortness of breath, chest pain or discomfort, or a feeling of tiredness or faintness.

CLASS IV

The patient is unable to perform any physical activity. Shortness of breath and/or a feeling of tiredness may occur at rest, and these symptoms worsen with almost any physical activity.

PULMONARY ARTERIAL HYPERTENSION

pulmonary arterial hypertension

Patients Who Have PAH

Patients who have PAH may have symptoms that are not specific to the disease, such as fatigue, dizziness, fainting, shortness of breath, or chest pain during exercise.

The combination of these nonspecific symptoms and the rare nature of the disease can make it hard to diagnose or can lead to a misdiagnosis.

In many patients, PAH is often not diagnosed until the disease has become worse.